2019 International Workstar Cooling System Parts

This table covers the engine coolants and antifreeze formulations specified for this cooling system. Typical signs include a rising temperature gauge, rusty or sludged coolant, or a heater that blows cold. Use the chemistry named in the notes. Mixing silicate, OAT and HOAT formulas can gel in the radiator. Read more

12 Coolant / Antifreeze parts are listed for the 2019 International Workstar, from PRESTONE, VALVOLINE and PEAK. PRESTONE AF3100 carries the "Popular" badge. 9 parts fit every engine; the other 3 are engine-specific.

The Compatible With All Colors section lists 1 option from PRESTONE — grouped under the catalog's "Compatible With All Colors" designation — the notes column spells out what sets them apart. PRESTONE AF3055 is listed in this group.

In the Economy grade, PRESTONE supplies 1 part: the catalog's value-priced group. A representative part number is PRESTONE AF3100.

The Heavy Duty section lists 7 options from PRESTONE, VALVOLINE and PEAK — rated for severe service. VALVOLINE ZXG051 is listed in this group.

The Premium section lists 2 options from PRESTONE — a step above OE specification in materials, tolerances or warranty terms. PRESTONE AF2100 is listed in this group.

The Standard Replacement section lists 1 option from VALVOLINE — built to original-equipment specification. VALVOLINE 861399 is listed in this group.

This table covers the Coolant filters. Typical signs include restricted flow — long cranking, weak airflow, or dirty fluid after a short interval. Seat the new filter so it cannot bypass, and use the grade the notes call for. Read more

One part is listed for the 2019 International Workstar — HASTINGS / BALDWIN LOPRI.

This table covers the Coolant Level sensors. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors. Read more

GPD supplies the 3 Coolant Level Sensor parts for the 2019 International Workstar.

This group includes GPD 1816403, GPD 1816610 and GPD 1816611.

This table covers the caps on the overflow / expansion tank. Typical signs include a leak at the neck, a cap that will not hold pressure, or a missing tether. Match the pressure rating or thread in the notes — radiator, reservoir and fuel caps are not interchangeable. Read more

2 Coolant Reservoir Cap parts for the 2019 International Workstar come from 2 brands — GATES and MOTORAD.

Part numbers include GATES 31405 and MOTORAD T39.

This table covers the adapters used to pressure-test this cooling system. Read more

GATES supplies both parts for the 2019 International Workstar.

Listed part numbers: GATES 31379 and GATES 31410.

This table covers the Hose clamps. Read more

One part is listed for the 2019 International Workstar — DORMAN 9044000.

This table covers the intercoolers that cool turbo or supercharger charge air. Read more

One part is listed for the 2019 International Workstar — GPD 2711626.

This table covers the Intercooler Air Hose pipes. Read more

GATES supplies the 3 Intercooler Air Hose / Pipe parts for the 2019 International Workstar.

This group includes GATES 26200, GATES 26201 and GATES 26203.

This table covers the radiators that dump engine heat to airflow through the core. Typical signs include overheating in traffic, a wet core, or coolant that disappears with no puddle. Replace the cap if it cannot hold the rated pressure, and bleed the system after the swap. Read more

One part is listed for the 2019 International Workstar — SPECTRA PREMIUM 20013564P.

This table covers the upper, lower and connecting hoses between radiator, engine and reservoir. Typical signs include swelling, cracks, a soft spot, or a leak at a clamp. Replace adjacent aged hoses while the system is drained — they share the same heat cycle. Read more

This group shows a single part: DAYCO 71813.

This table covers the thermostats that open the coolant circuit at the specified temperature. Typical signs include slow warm-up, a gauge that climbs in traffic, or heat that never quite arrives. Replace the housing gasket with the thermostat and bleed the system so a trapped air pocket does not cook the new part. Read more

9 Thermostat parts for the 2019 International Workstar come from 4 brands — MOTORAD, CALORSTAT, GATES and 1 other brand.

Heavy Duty: 1 part, from GATES. A representative part number is GATES 34308.

Standard Replacement: 2 parts, from MOTORAD. A representative part number is MOTORAD 407160.

6 further parts sit outside the graded sections, with the same engine-level match.

Listed part numbers: GATES 34308, MOTORAD 407160 and MOTORAD 407180, plus the other parts above.

This table covers the pumps that circulate coolant through the block and radiator. Typical signs include coolant at the weep hole, pulley play, or a growl from the front of the engine. Replace the thermostat and refill with the specified coolant whenever the pump comes off. Read more

5 Water Pump parts for the 2019 International Workstar come from 5 brands — FVP, US MOTOR WORKS, MELLING and 2 other brands.

The High Volume / Pressure section lists 2 options from FVP and US MOTOR WORKS — grouped under the catalog's "High Volume / Pressure" designation — the notes column spells out what sets them apart. FVP US7123H is listed in this group.

Standard Replacement: 1 part, from MELLING. A representative part number is MELLING MWP521.

2 further parts sit outside the graded sections, with the same engine-level match.

Listed part numbers: FVP US7123H and MELLING MWP521, plus the other parts above.